A Two Day Marine chronometer
by Thomas Mercer Limited, St Albans, no. 23990. 4in(10cm)diam. silvered dial with blackened Roman numerals,with separate seconds and state of wind dials. Fusee movement and Earnshaw escapement. On locking brass gimbal mount in a mahogany case with glass window, inside a mahogany deck box with leather strap. 11x10x8in(28x25x20cm)